46results about "Azeotropic/extractive distillation" patented technology

The invention relates to a venturi separator, which is characterized in that the venturi separator comprises a venturi tube and a liquid phase collecting tube surrounding at least one part of structure of the venturi tube, and the venturi tube comprises the following sections which are communicated in sequence: an optional equal-diameter section, a reducing section, a throat part and an expanding section, the venturi separator is provided with a gas phase inlet, a liquid phase inlet, a liquid phase outlet and a gas phase outlet, an opening is formed in the side wall or the tail end of the expanding section of the venturi tube, and the opening leads to the liquid phase collecting tube, so that a liquid phase leaves the venturi tube and enters the liquid phase collecting tube under the action of centrifugal force. The invention also relates to the use of such a Venturi separator in a chemical process.

The present disclosure provides methods and systems for producing a C4+ compound, including the steps of: (i) reacting a feed stream comprising C1+O1-3 hydrocarbons in the presence of an acid condensation (AC) catalyst at a condensation temperature and condensation pressure to produce an AC product stream including the C4+ compound; (ii) fractionating AC product stream into an AC liquid product stream including organic products and a vapor stream; (iii) fractionating the AC liquid product stream by a fractionation column into a liquid C4+ compound product stream and a gaseous overhead stream; (iv) cooling the gaseous overhead stream to produce a liquid reflux stream and a gaseous vent stream; (v) recycling a first portion of the liquid reflux stream to the fractionation column for the fractionation in step (iii); and (vi) recycling a second portion of the liquid reflux stream to the feed stream for the reaction in step (i).

The present disclosure provides an α-olefin extractant and a method for separating an alkane and an α-olefin, wherein the α-olefin extractant comprises an alcohol-amine, a saturated monoketone having a carbon chain length of 7-10 and a monovalent salt of a Group IB metal, wherein the alcohol-amine, the saturated monoketone having a carbon chain length of 7-10 and the monovalent salt of a Group IB metal are in a mass ratio of (0.9-2.0):(0.8-1.5):(0.1-0.6). In the present disclosure, the technical principle of complexing extractive rectification is utilized and achieves the purpose of separating an olefin from an alkane by adding a complexing extractant to form a relatively stable complex between a metals and the olefin. The present disclosure has advantages of good separation effect and high product yield.

An apparatus, in particular for separating and purifying styrene from a crude mixture comprising styrene, comprises a steam generating unit and a divided wall distillation column wherein the divided wall distillation column comprises a divided wall comprising a first portion, the first portion extends at least substantially vertically downward from a point located below the top of the distillation column to a point located above the bottom of the divided wall distillation column so as to subdivide the divided wall distillation column into: a top section located above the dividing wall; a bottom section below the partition wall; and a middle section comprising a first middle sub-section on one side of the first portion of the partition wall and a second middle sub-section on an opposite side of the first portion of the partition wall, where the partition wall further comprises a second portion connected to an upper portion of the first portion of the partition wall, at least one part of the bottom section, which extends at least over 10% of the height of the divided wall distillation column, has a smaller cross-sectional area than the middle section of the divided wall distillation column, and wherein at least one part of the bottom section, which extends at least over 10% of the height of the divided wall distillation column, has a smaller cross-sectional area than the middle section of the divided wall distillation column, the dividing wall type distillation column further comprises a feed inlet pipeline, an extraction solvent inlet pipeline, a steam inlet pipeline connected with the steam generating unit, an overhead outlet pipeline, a bottom outlet pipeline and a side outlet pipeline connected with the second middle sub-section of the dividing wall type distillation column, the plant further comprises a side condenser and a liquid-liquid separator, where the side outlet line is connected to the side condenser and downstream thereof to the liquid-liquid separator, where the liquid-liquid separator is connected to the water line leading into the steam generating unit.

The utility model discloses a constant-temperature structure of aromatic hydrocarbon solvent distillation equipment, which relates to the technical field of aromatic hydrocarbon extraction and comprises a base, a heating seat fixedly connected to the upper end of the base, a constant-temperature tank fixedly connected to the upper end of the heating seat, a distillation retort arranged inside the constant-temperature tank, and a fixing frame fixedly connected to the outer surface of the distillation retort. The fixing frame is fixedly connected with the inner wall of the constant-temperature tank, a distillation outlet is formed in the upper end of the distillation tank, a feeding port is formed in the side face of the distillation tank, a liquid level control mechanism is arranged at the feeding port, a heating component and a constant-temperature module are arranged between the constant-temperature tank and the distillation tank, and a moving unit is arranged at the lower end of the base. The aromatic hydrocarbon solvent is heated and distilled through the heating component, heating is uniform, the aromatic hydrocarbon solvent is subjected to constant-temperature distillation through the constant-temperature module, and the distillation efficiency and the distillation effect are improved; and through the liquid level control mechanism, when the liquid level is low, the aromatic solvent can be automatically added, so that the influence on distillation caused by unknown distillation of the aromatic solvent or too little aromatic solvent is avoided.

An integrated process for upgrading a hydrocarbon oil feed stream using a delayed coking unit, a steam enhanced catalytic cracking unit, and an aromatic compounding unit, the process comprising solvent deasphalting the hydrocarbon oil stream; carrying out delayed coking on the heavy residual hydrocarbons; hydrotreating the delayed coker product stream and the deasphalted oil stream to form a C3-C4 hydrocarbon stream, a light C5 + hydrocarbon stream, and a heavy C5 + hydrocarbon stream; subjecting the C3-C4 hydrocarbon stream to dehydrogenation to form propylene and butene; subjecting the light C5 + hydrocarbon stream to steam enhanced catalytic cracking; subjecting the heavy C5 + hydrocarbon stream to steam enhanced catalytic cracking; passing at least a portion of the light steam enhanced catalytic cracking stream, the heavy steam enhanced catalytic cracking stream, or both to a product separator to produce an olefin product stream, a naphtha product stream, and a BTX product stream; and treating the naphtha product stream in the aromatics compounding unit to produce benzene and xylenes.

The present invention relates to a Venturi separator, characterized in that the Venturi separator comprises a Venturi tube and a liquid-phase collector tube which encloses at least a part of the structure of the Venturi tube, wherein the Venturi tube comprises the following sequentially connected sections: an optional constant-diameter section, a reduced-diameter section, a neck and an expanded-diameter section, and the Venturi separator has a gas-phase inlet, a liquid-phase inlet, a liquid-phase outlet and a gas-phase outlet, wherein an opening is provided on a side wall of the expanded-diameter section of the Venturi tube or at the end of the expanded-diameter section, the opening leading to the liquid-phase collector tube so that a liquid phase can leave the Venturi tube and enter the liquid-phase collector tube under centrifugal force.The present invention also relates to the use of the Venturi separator in chemical processes.

The present disclosure provides methods and systems for producing a C4+ compound, including the steps of: (i) reacting a feed stream comprising C1+O1-3 hydrocarbons in the presence of an acid condensation (AC) catalyst at a condensation temperature and condensation pressure to produce an AC product stream including the C4+ compound; (ii) fractionating AC product stream into an AC liquid product stream including organic products and a vapor stream; (iii) fractionating the AC liquid product stream by a fractionation column into a liquid C4+ compound product stream and a gaseous overhead stream; (iv) cooling the gaseous overhead stream to produce a liquid reflux stream and a gaseous vent stream; (v) recycling a first portion of the liquid reflux stream to the fractionation column for the fractionation in step (iii); and (vi) recycling a second portion of the liquid reflux stream to the feed stream for the reaction in step (i).

This disclosure provides an α-alkene extractant comprising an alcoholamine, a saturated monoketone having a carbon chain length of 7-10, and a monovalent salt of a Group IB metal, wherein the mass ratio of the alcoholamine, the saturated monoketone having a carbon chain length of 7-10, and the monovalent salt of the Group IB metal is (0.9-2.0):(0.8-1.5):(0.1-0.6), and a method for separating alkanes and α-alkenes. This disclosure utilizes the principle of complexation extractive rectification technology, and by adding a complexation extractant, a relatively stable complex is formed between the metal and the alkene, achieving the goal of separation from the alkane, with good separation efficiency and high product yield.

A process including heating a hydrogen manufacturing unit feedstock producing a heated hydrogen manufacturing unit feedstock. The process includes stripping a wide boiling range hydrocarbon mixture with heated hydrogen manufacturing unit feedstock producing an overheads stream, separating the overheads stream to recover a non-condensed stream, and feeding the non-condensed stream to a hydrogen manufacturing unit. A process including feeding a hydrocarbon manufacturing unit feedstock to a stripping unit, recovering an overhead stream, feeding the overhead stream to a separation unit separating the hydrogen manufacturing unit feedstock from light boiling hydrocarbons, feeding a portion of the separated hydrogen manufacturing unit feedstock stream to a hydrogen manufacturing unit producing a hydrogen stream, feeding a first portion of the hydrogen stream and the bottoms stream to a first hydroprocessing unit, and feeding a second portion of the hydrogen stream, the first effluent, and the recovered medium boiling hydrocarbons to a second hydroprocessing unit.

A system comprising fractionation module 300 fluidly coupled with water wash module 500 (figure 5) which receives hydrogenated hydrocarbon material generatable from plastic waste and outputs steam-diluted hydrocarbon material. The fractionation module comprises a fractionation tower 302 comprising: a first section 310a positionable to strip the hydrogenated hydrocarbon material in a steam environment; a second section 310b offset from the first positionable to rectify the hydrogenated hydrocarbon material in a steam environment. The water wash module is positionable to receive steam-diluted hydrocarbon material and output purified steam cracker feedstock. The water wash module comprises a circulation loop 504a (figure 5) extending from a first end of a compartment 502 (figure 5) to the second end. The fractionation module can comprise a condenser 305 to split a portion from the steam-diluted hydrocarbon material and a processing chamber 304 fluidly coupled to the fractionation tower to recycle the portion therein. A method comprising a hydrogenation module receiving contaminated hydrocarbon material generated from waste plastic, which outputs hydrogenated hydrocarbon material subsequently transmitted to the fractionation module as described above wherein it is stripped and rectified in a steam environment to generate steam-diluted hydrocarbon material subsequently fed to the above-described wash module.

The present application relates to an extractive distillation column comprising, from bottom to top, a tray section, a movable section and a packing section; the packing section comprises gas-liquid contact mass transfer elements referred to as first packing; the movable section comprises gas-liquid contact mass transfer elements referred to as second packing, or comprises a packing-tray composite which is a composite of gas-liquid contact mass transfer elements referred to as third packing and gas-liquid contact mass transfer elements referred to as first stereo-spray tray; the tray section comprises gas-liquid contact mass transfer elements referred to as second stereo-spray tray, wherein the extractive distillation column further comprises an extractant inlet, a feedstock inlet, a top vapor outlet, a bottom liquid outlet and optionally a side inlet, and the packing section is located above the extractant inlet; the movable section is located between the extractant inlet and the feedstock inlet; the tray section is located below the feedstock inlet. The present application also relates to an extractive distillation system comprising the above extractive distillation column and an extractive distillation method using the extractive distillation system.

In accordance with one or more embodiments herein, an integrated process for upgrading a hydrocarbon oil feed stream utilizing a delayed coker, steam enhanced catalytic cracker, and an aromatics complex includes solvent deasphalting the hydrocarbon oil stream; delayed coking the heavy residual hydrocarbons; hydrotreating the delayed coker product stream and the deasphalted oil stream to form a light C5+ hydrocarbon stream and a heavy C5+ hydrocarbon stream; steam enhanced catalytically cracking the light C5+ hydrocarbon stream; steam enhanced catalytically cracking the heavy C5+ hydrocarbon stream; passing at least a portion of the light steam enhanced catalytically cracked stream, the heavy steam enhanced catalytically cracked stream, or both to a product separator to produce a olefin product stream, a naphtha product stream, and a BTX product stream; and processing the naphtha product stream in the aromatics complex to produce benzene and xylenes.

Provided is a method for preparing synthesis gas and aromatic hydrocarbons, and more particularly, a method for preparing synthesis gas and aromatic hydrocarbons including: supplying a pyrolysis fuel oil (PFO) stream containing PFO and a pyrolysis gas oil (PGO) stream containing PGO to a distillation tower as a feed stream (S10), the PFO stream and the PGO stream being discharged from a naphtha cracking center (NCC) process; and supplying a lower discharge stream from the distillation tower to a combustion chamber for a gasification process and supplying an upper discharge stream from the distillation tower to an SM / BTX preparation process (S20).

The invention relates to an extractive distillation tower. The extractive distillation tower sequentially comprises a tower plate layer, a movable layer and a filler layer from bottom to top, the filler layer comprises a gas-liquid contact mass transfer element called a first filler; the movable layer comprises a gas-liquid contact mass transfer element called as a second filler, or comprises a filler tower plate composite body, and the filler tower plate composite body is a composite body of a gas-liquid contact mass transfer element called as a third filler and a gas-liquid contact mass transfer element called as a first three-dimensional jet tower plate; the tower plate layer comprises a gas-liquid contact mass transfer element called a second three-dimensional jet tower plate, the extractive distillation tower further comprises an extraction solvent inlet, a raw material inlet, a tower top gas phase outlet, a tower bottom liquid phase outlet and an optional side line inlet, and the filler layer is located above the extraction solvent inlet; the movable layer is positioned between the extraction solvent inlet and the raw material inlet; and the tower plate layer is positioned below the raw material inlet. The invention also relates to an extractive distillation system comprising the extractive distillation tower and an extractive distillation method using the extractive distillation system.

This disclosure provides an α-alkene extractant comprising an alcoholamine, a saturated monoketone having a carbon chain length of 7-10, and a monovalent salt of a Group IB metal, wherein the mass ratio of the alcoholamine, the saturated monoketone having a carbon chain length of 7-10, and the monovalent salt of the Group IB metal is (0.9-2.0):(0.8-1.5):(0.1-0.6), and a method for separating alkanes and α-alkenes. This disclosure utilizes the principle of complexation extractive rectification technology, and by adding a complexation extractant, a relatively stable complex is formed between the metal and the alkene, achieving the goal of separation from the alkane, with good separation efficiency and high product yield.

An integrated process for upgrading a hydrocarbon oil feed stream includes solvent deasphalting the hydrocarbon oil stream; processing the heavy residual hydrocarbons in a gasification unit to form syngas and gasification residue; hydrotreating the deasphalted oil stream to form a C3-C4 hydrocarbon stream, a light C5+ hydrocarbon stream, and a heavy C5+ hydrocarbon stream; dehydrogenating the C3-C4 hydrocarbon stream to form propylene and butylene; steam enhanced catalytically cracking the light C5+ hydrocarbon stream; steam enhanced catalytically cracking the heavy C5+ hydrocarbon stream; passing at least a portion of the light steam enhanced catalytically cracked stream, the heavy steam enhanced catalytically cracked stream, or both to a product separator to produce a olefin product stream, a naphtha product stream, and a BTX product stream; and processing the naphtha product stream in the aromatics complex to produce benzene and xylenes.

An integrated process for upgrading a hydrocarbon oil feed stream includes solvent deasphalting the hydrocarbon oil stream; processing the heavy residual hydrocarbons in a gasification unit to form syngas and gasification residue; hydrotreating the deasphalted oil stream to form a C3-C4 hydrocarbon stream, a light C5+ hydrocarbon stream, and a heavy C5+ hydrocarbon stream; dehydrogenating the C3-C4 hydrocarbon stream to form propylene and butylene; steam enhanced catalytically cracking the light C5+ hydrocarbon stream; steam enhanced catalytically cracking the heavy C5+ hydrocarbon stream; passing at least a portion of the light steam enhanced catalytically cracked stream, the heavy steam enhanced catalytically cracked stream, or both to a product separator to produce a olefin product stream, a naphtha product stream, and a BTX product stream; and processing the naphtha product stream in the aromatics complex to produce benzene and xylenes.

The present invention concerns a process for manufacture of C6−C8 aromatic hydrocarbons from pre-sorted fractions from end-of-life vehicles (first feedstock) using at least one gasifier. Said first feedstock F1 and a second feedstock are converted in at least one gasifier into a first raw synthesis gas RSG1, wherein said first raw synthesis gas RSG1 comprises CO, H2, and C6−C8 aromatic hydrocarbons. Next, said C6−C8 aromatic hydrocarbons are removed from said first raw synthesis gas RSG1 by a gas cleaning process GC in a gas cleaning unit GCU, whereby a clean first synthesis gas CSG1 and a first liquid residue LR1 are formed. Next, an aromatic stream AS and a second liquid stream LR2 are removed from said first liquid residue LR1 in an aromatic hydrocarbon extraction unit AEU, wherein said aromatic stream AS is enriched in C6−C8 aromatic hydrocarbons and wherein said second liquid stream LR2 is depleted in C6−C8 aromatic hydrocarbons.

The utility model discloses equipment for purifying thiophene by azeotropic distillation of crude benzene, which comprises a mounting plate, and the upper surface of the mounting plate is fixedly connected with a primary distillation tower, a benzene fraction tower, an extractive distillation tower and an extractant regeneration tower respectively. The device is provided with a primary distillation tower, a benzene fraction tower, an extractive distillation tower, an extractant regeneration tower, an extraction secondary distillation tower, an extractant secondary regeneration tower, a thiophene refining tower, a hydrogenation feeding buffer tank, a benzene fraction assembly and a benzene hydrogenation removal system, and then a carbon disulfide product meeting the requirements is produced by adopting common distillation and precise distillation modes. According to the technology for extracting thiophene from crude benzene, high-added-value thiophene and carbon disulfide in crude benzene are separated and purified through a rectification process by utilizing the difference of boiling points and polarities of various substances in crude benzene, the recycling of thiophene and carbon disulfide in crude benzene is a physical process, and compared with synthesis of thiophene with butylene and sulfur and synthesis of carbon disulfide with natural gas and sulfur, the technology has the advantages that the cost is low; and the production process is safer and more reliable.

An integrated process for upgrading a hydrocarbon oil feed stream utilizing a delayed coker, steam enhanced catalytic cracker, and an aromatics complex includes solvent deasphalting the hydrocarbon oil stream; delayed coking the heavy residual hydrocarbons; hydrotreating the delayed coker product stream and the deasphalted oil stream to form a C3-C4 hydrocarbon stream, a light C5+ hydrocarbon stream, and a heavy C5+ hydrocarbon stream; dehydrogenating the C3-C4 hydrocarbon stream to form propylene and butylene; steam enhanced catalytically cracking the light C5+ hydrocarbon stream; steam enhanced catalytically cracking the heavy C5+ hydrocarbon stream; passing at least a portion of the light steam enhanced catalytically cracked stream, the heavy steam enhanced catalytically cracked stream, or both to a product separator to produce a olefin product stream, a naphtha product stream, and a BTX product stream; and processing the naphtha product stream in the aromatics complex to produce benzene and xylenes.

The invention relates to an extractive distillation tower. The extractive distillation tower, from bottom to top, sequentially comprises a tower tray layer, an active layer, and a packing material layer; the packing material layer comprises a gas-liquid contact mass transfer element hereinafter called the first packing material; the active layer comprises a gas-liquid contact mass transfer element hereinafter called the second packing material, or comprises a packing material / tower tray composite body, said body being a gas-liquid contact mass transfer element hereinafter called the third packing material and a gas-liquid contact mass transfer element composite body hereinafter called the first 3D jet tower tray; the tower tray layer comprises a gas-liquid contact mass transfer element hereinafter called the second 3D jet tower tray; the extractive distillation tower further comprises an extraction solvent inlet, a raw material inlet, a tower top gas phase outlet, a tower bottom liquid phase outlet and an optional side stream inlet; the packing material layer is located above the extraction solvent inlet; the active layer is located between the extraction solvent inlet and the raw material inlet; and the tower tray layer is located below the raw material inlet. The present invention further relates to an extractive distillation system comprising the extractive distillation tower and an extractive distillation method using the extractive distillation system.

The present disclosure provides an α-olefin extractant and a method for separating an alkane and an α-olefin, wherein the α-olefin extractant comprises an alcohol-amine, a saturated monoketone having a carbon chain length of 7-10 and a monovalent salt of a Group IB metal, wherein the alcohol-amine, the saturated monoketone having a carbon chain length of 7-10 and the monovalent salt of a Group IB metal are in a mass ratio of (0.9-2.0):(0.8-1.5):(0.1-0.6). In the present disclosure, the technical principle of complexing extractive rectification is utilized and achieves the purpose of separating an olefin from an alkane by adding a complexing extractant to form a relatively stable complex between a metals and the olefin. The present disclosure has advantages of good separation effect and high product yield.

A process for producing desulfurized alpha olefins may include reacting a conjugated diene compound and a hydrocarbon oil stream including alpha olefins in a Diels-Alder reactor at a temperature of 100 ℃ to 250 ℃ to form an effluent stream including adducts of the conjugated diene compound and the alpha olefins, subjecting the effluent stream to a hydrodesulfurization catalyst and a hydrogen stream in a hydrodesulfurization reactor to produce a hydrodesulfurized effluent stream including the adducts, a saturated C5+ hydrocarbon stream, and a gaseous stream, separating the adducts, the saturated C5+ hydrocarbon stream, and the gaseous stream, and cracking the adducts in a first thermal cracking reactor operating at a temperature greater than 250 ℃ to produce a decomposed adducts stream including an alpha olefin stream and a recovered conjugated diene compound stream, wherein the gaseous stream includes hydrogen, sulfides, C1-C4 saturated hydrocarbons, or combinations thereof.

An integrated process for upgrading a hydrocarbon oil feed stream utilizing a delayed coker, steam enhanced catalytic cracker, and an aromatics complex includes solvent deasphalting the hydrocarbon oil stream; delayed coking the heavy residual hydrocarbons; hydrotreating the delayed coker product stream and the deasphalted oil stream to form a C3-C4 hydrocarbon stream, a light C5+ hydrocarbon stream, and a heavy C5+ hydrocarbon stream; dehydrogenating the C3-C4 hydrocarbon stream to form propylene and butylene; steam enhanced catalytically cracking the light C5+ hydrocarbon stream; steam enhanced catalytically cracking the heavy C5+ hydrocarbon stream; passing at least a portion of the light steam enhanced catalytically cracked stream, the heavy steam enhanced catalytically cracked stream, or both to a product separator to produce a olefin product stream, a naphtha product stream, and a BTX product stream; and processing the naphtha product stream in the aromatics complex to produce benzene and xylenes.

The present invention relates to a process for separating butenes from a C4 hydrocarbon stream containing butenes and butanes by extractive distillation using a suitable solvent. The process according to the invention is characterized by heat integration, using the heat of the solvent to heat and / or at least partially vaporize various streams, and by the use of a heat pump to electrify the process.

The invention relates to a Venturi separator, characterized in that the Venturi separator comprises a Venturi tube and a liquid phase collecting tube surrounding at least a part of the structure of the Venturi tube. The Venturi tube comprises the following sections which are sequentially communicated: an optional equal-diameter section, a diameter-reducing section, a throat part and a diameter-expanding section. The Venturi separator is provided with a gas phase inlet, a liquid phase inlet, a liquid phase outlet and a gas phase outlet. An opening is formed in the side wall of the diameter-expanding section or the tail end of the diameter-expanding section of the Venturi tube. The opening leads to the liquid phase collecting tube, so that the liquid phase leaves the Venturi tube under the action of centrifugal force and enters the liquid phase collecting tube. The invention also relates to a use of the Venturi separator in a chemical process.

An apparatus, in particular for the separation and purification of styrene from a crude mixture comprising styrene, comprises a steam generation unit, a liquid-liquid extraction scrubber column and a distillation column, where the distillation column comprises a top section and a bottom section, where the top section and the bottom section are separated from each other. At least a portion of the bottom section, preferably extending over 10% of the height of the distillation column, has a smaller cross-sectional area than the top section of the distillation column, the distillation column further comprises a feed inlet line, an extraction solvent inlet line, a steam inlet line connected to the steam generation unit, a top outlet line, a bottom outlet line, and a side outlet line arranged below the top outlet line and above the bottom outlet line, the tower top outlet line is directly connected to the liquid-liquid extraction scrubbing tower, or the tower top outlet line is directly or indirectly connected to a liquid-liquid separator comprising a water outlet line and a hydrocarbon outlet line, the water outlet line is connected to the liquid-liquid extraction scrubbing tower and the side outlet line is directly connected to the liquid-liquid extraction scrubbing tower, and the hydrocarbon outlet line is connected to the liquid-liquid separator. Or the side outlet line is directly or indirectly connected to a liquid-liquid separator comprising a water outlet line and a hydrocarbon outlet line, the hydrocarbon outlet line being connected to the liquid-liquid extraction scrubbing column, and the water outlet line of the liquid-liquid separator leading into the steam generation unit.

A plant in particular for separating and purifying styrene from a crude mixture comprising styrene comprises a steam generating unit and a dividing-wall distillation column, wherein the dividing-wall distillation column comprises a dividing wall comprising a first portion extending at least essentially vertically downwards from a point being located below the top of the distillation column to a point being located above the bottom of the dividing-wall distillation column so as to subdivide the dividing-wall distillation column into a top section being located above the dividing- wall, into a bottom section being located below the dividing-wall and into a middle section comprising a first middle subsection being located on one side of the first portion of the dividing wall and a second middle subsection being located on the opposite side of the first portion of the dividing wall, wherein the dividing wall further comprises a second portion being connected with an upper part of the first portion of the dividing wall and extending into the second middle subsection to the inner wall of the dividing-wall distillation column, wherein at least a part of the bottom section extending at least over 10% of the height of the dividing-wall distillation column has a smaller cross-sectional area than the middle section of the dividing-wall distillation column, wherein the dividing-wall distillation column further comprises an inlet line for feed, an inlet line for extractive solvent, an inlet line for steam being connected with the steam generating unit, an overhead outlet line, a bottom outlet line and a side outlet line being connected with the second middle subsection of the dividing-wall distillation column, wherein the plant further comprises a side condenser and a liquid-liquid separator, wherein the side outlet line is connected with the side condenser and downstream thereof with the liquid-liquid separator, wherein the liquid-liquid separator is connected with a water line which leads into the steam generating unit.